The objective of this project is to elucidate the properties and function of the "transfer" factor or factors present in the RNA extracted from C57B1/6J mice that have rejected A/J mouse sarcoma 1 (Sal) tumors. This proposal is primarily concerned with the isolation, purification and characterization of those factors in RNA which allow it to "convert" in vitro spleen cells from nonimmune C57B1 mice to a state of specific tumor immunity, presumably of the cell-mediated type, as detected by the technique of spleen cell migration inhibition developed by the Principal Investigator. In addition, it is proposed to reinfuse the RNA "converted" spleen cells into syngeneic nonimmune C57B1 mice to determine if these mice will now reject Sal tumors in an accelerated manner. Finally, it is proposed to expose allogeneic A/J mouse spleen cells in vitro to the C57B1 mouse RNA to determine if a reinfusion of these cells into A/J recipients will permit these animals to reject the Sal tumors which normally kill them. The availability of the information that we propose to gather may eventually result in the development of similar procedures using human tumors, thereby leading to more reliable adoptive immunotherapeutic methods than currently available in the management of malignant disease. We speculate that such immunotherapeutic procedures would minimize and avoid complications due to secondary allogeneic disease (graft versus host reactions) and immunologic enhancement.